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Diterpenoides de Plantas do Genero Teucrium/Productos Naturais do Fundo Phellinus Pini

By Ana Maria Lourenco

Abstract

The first part of this thesis s dedicated to the establishment of the structures of new neo-clerodan diterpenoids. From study of the chemical constituents of the aerial parts of Teucrium gracile, five diterpenoids are identified. Four of these metabolites have new structures: teugracilin B, teugracilin C and 3-O-deacetilteugracilin A. The fifth metabolite isolated, teumicropodin, had already been extracted from Teucrium. The absolute configurations proposed fro four neo-clerodanes - montanin C, 12-epiteupolin II, teugnaphalodin and teubutilin B - is confirmed on the basis of the chemical correlation with 19-acetilgnafalin derivatives (the 19-acetilgnafalin is a neo-clerodane which absolute stereochemistry is well known). The stereochemistry of the quiral center at C-8 of two Known neo-clerodanes, isocrotocaudin and crotocaudin, was corrected from 8(S) to 8(R). The starting material is montanin A, and the final product isocrotocaudin. The configuration at the C-8 quiral center of crotocaudin is also established because of its chemical correlation with isocrotocaudin. The last part of the work done on neo-clerodane diterpenoides is the comparative study of "1HRMN and molecular rotation data of this type of compounds that posses at the C-12 position a hydroxyl, acetate or benzoate substituent, for the determination of a method that makes possible the attribution of the absolute configuration at that asymmetric center, even if just one of the epimers is available. The second part of this thesis includes the chemical study of the fungus Phellinus pini. The extracts of dichloromethane and methanol were studied and from the first it is isolated a ceramide -N-(2'-hydroxyhexacosanoyl)-D-erythro-1,3,4-trihydroxy-2-amino-octane and N-(2'-hydroxyheptacosanoyl)-D-erythro-1,3,4-trihydroxy-2-amino-octane four sterols - 5#alpha#-ergosta-7,24(28)-diene-3#beta#-ol (episterol), 5#alpha#-ergosta-7-ene-3#beta#-ol, 5#alpha#-ergosta-23-ene-3#beta#-ol e 5#alpha#, 8#alpha#-epidioxiergosta-6,22-diene-3#beta#-ol, one lignan -2:6-bis-(4-hydroxy-3-metoxiphenyl)-3:7-dioxabicyclo[3,3,0]octane [(+)pinoresinol], one series of fatty acids from C_2_2 to C_2_6, on the form of its methyl esters and one homologous series of fatty acids from C_2_2, C _2_4 and C_2_6, esterified with long chain alcohols from C_2_3, C_2_4 to C_2_5. From the methanol extract a sugar is isolated on its peracetilated form - octa-O-acetil-#alpha#,#alpha#"'-trealose (after acetilation)Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga

Topics: 07C - Organic chemistry
Year: 1992
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Provided by: OpenGrey Repository
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